Circuit breaker



April 8, 1958 J. A. HERRMANN EI'ALI CIRCUIT BREAKER 3 Sheets-Sheet 1 Filed April 28, 1954 INVENTORS.

April 8, 1958 J. A. HERRMANN ETAL CIRCUIT BREAKER 3 Sheets-Sheet 2 Filed April 28, 1954 INVENTORS 77 fl/rerrmarzrz Y/II/ll/l/ J. A! HERRMANN E AL CIRCUIT BREAKER April s, 1958 3 Sheets-Sheet 3 Filed April 28, 1954 IN V EN TOR. J51 xgflerrmann BY 1710003 2'' 7/225? United States atent CIRCUIT BREAKER John A. Herrmann, Grosse Pointe Farms, and Elwood T. Platz, Detroit, Mich., assignors, by mesne assignments, to I-T-E Circuit Breaker Company, Philadelphia, Pa.,

a corporation of Pennsylvania Application April 28, 1954, Serial No. 426,223

9 Claims. (Cl. 200-116) This invention relates to circuit breakers generally and particularly to multipole circuit breakers used in load centers and lighting and distribution panelboards.

A primary object of this invention is to provide a multipole circuit breaker mechanism which is automatically reset, upon automatic tripping thereof, for manual movement to the closed circuit position.

Another object is to provide an automatic resettable multipole circuit breaker which obtains uniform manual operation uopn actuation to the open and closed circuit positions.

Another object is to provide a multipole circuit breaker having a novel reversible operating mechanism.

Still another object is to provide an automatic resettable multipole circuit breaker wherein the automatic tripping mechanism is utilized to actuate the circuit breaker mechanism to open circuit position upon manual operation.

The above objects, features, and advantages of the present invention will be more fully understood from the following description considered in connection with the accompanying illustrative drawings in which:

Fig. 1 is a front elevational view of a panelboard containing an embodiment of the invention.

Fig. 2 is an exploded view of certain parts of an embodiment of the invention.

Fig. 3 is an enlarged partial plan view of an embodiment of the circuit breaker operating mechanism.

Fig. 4 is a partial cross-sectional view as if on line 44 of Fig. 3, showing an embodiment of the circuit breaker mechanism in the closed circuit position.

Fig. 5 is a partial cross-sectional view as if on line 5-5 of Fig. 1, showing an embodiment of the circuit breaker mechanism in an intermediate position between circuit closed and circuit open position.

Fig. 6 is a partial cross-sectional view as if on line 66 of Fig. 1, showing an embodiment of the circuit breaker mechanism in the open circuit position.

Referring now to Fig. 1, which shows a panelboard 11 employing three-pole embodiments of a multipole circuit breaker invention denoted generally as 12, in which the breakers are arranged in two vertical rows as shown and supplied with electric power through suitable bus conductors (not shown). The particular handle structure included in this invention, and hereinafter described, permits uniform handle movement for open and closed circuit positions regardless of the horizontal or vertical positioning of the breaker in either of the two vertical rows of the panelboard. Such a circuit breaker 12 includes a control mechanism 20 which functions to interrupt the flow of electric current in all three circuits connected to the circuit breaker upon the occurrence of a fault current in one or more of the circuits. Typically, the particular circuit breaker embodiment shown is used to control three-phase current and protect the branch circuit wiring and electrical equipment utilizing such current from the effects of overload and short circuit currents. The particular control mechanism shown is basically similar to that shown in prior issued patents, 1,794,901, issued March 3, 1931, to O. S. Jennings; 2,044,157, issued June 16, 1936, to H. D. Dorfman; and 1,985,023, issued December 18, 1934, to H. D. Dorfman. This control mechanism is enclosed in a housing 14 of dielectric material having a shield 15 (Fig. 2) of insulating material and a cover 16 of metal, which contains tapped holes 61 and 62 which receive a pivot member 57 to mount a rotary operator 54, as hereinafter described. A shoulder extends downwardly from tapped hole 62 to provide a mounting pivot for barrier 15a made of insulating material inserted between shield 15 and cover 16 and which surrounds handle 53 to close handle slot 51 as the handle 53 is moved from one circuit position to the other in slot 51. Appropriate line and load terminal connectors (not shown) are provided on opposite ends of the breaker for attachment of phase line and load circuit conductors.

The control mechanism, as shown in the closed circuit position of Fig. 4, serves to control all poles of the breaker and includes a frame 21 upon which a cradle 22 cut back, as shown in Figs. 4, 5, and 6, is pivoted for rotation about pivot pin 23. An operating member 24, having a handle 53, is pivoted for rotation about pivot pins 26 in opposite sides of frame 21, and a pair of tension springs 27 are attached at their outer ends to opposite sides of the upper portion of operating member 24 and at their inner ends to the knee pivot 28 of a pair of toggle links 29 and 30, which serve to operate pivoted switch arms 31, only one of which is shown for clarification. These switch arms 31 are mounted to pivot about a common pivot shaft 32 mounted on the frame 21. The link 29 transmits operating force to the switch arms 31 through the pivot 33. Secured to the ends of switch arms 31 is a tie bar 31a which extends across all three poles of the breaker and integrally connects all three switch arms 31 for initiating simultaneous movement to open and closed circuit positions. The toggle link 30 is pivotally connected to the cradle 22 by pivot pin 34. Each switch arm 31 carries a flexible leaf spring 35, upon the free end of which is mounted a movable contact 36 that is adapted to engage a stationary contact 37. With the breaker in the open circuit position of Fig. 6, the pivot 33 connecting link 29 and switch arms 31 is in alignment with pivot pins 26 which connect the lower portion of operating member 24 to the frame 21. Springs 27, link 29, and the lower portion of operating member 24 are in alignment. Springs 27 are stressed to maintain the alignment.

With the control mechanism 20 in the closed circuit position of Fig. 4, outer tip 41 of the cradle 22 is held by a latch 42. This latch 42 is pivoted at 42a and is biased in a clockwise direction (Figs. 4, 5, and 6) by a spring 43. Adjacent to latch 42 and engaging the outer end 44, as shown, is a common trip bar 45. Trip bar 45 is pivoted at 46 and extends across all three poles of the breaker. It is actuated upon the occurrence of a fault current in any branch circuit by a bimetallic trip member 47, which warps to the right upon overload. In the particular embodiment illustrated there is shown a manual trip member49 pivoted to operating member 24 at 48 and biased upwardly and to the right by a trip member spring 50 secured to a barrier 50a. The structure and functioning of this trip member 49 is more fully disclosed in copending application No. 342,174, filed March 13, 1953, and assigned to the assignee of the present application.

Extending through a slot 51 in shield 15 and cover 16 is a portion of handle stud 52 which is inserted into a tapped hole in operating member 24 (Figs. 4, 5, and 6). This stud 52 is threaded and mounts a tapped handle 53 made of insulating material. A rotary operator 54 engages a portion of handle 53 and provides circuit opening and circuit closing by rotary motion. As shown in Fig. 2, this handle contains a hole 55 which receives a pivot member 56 having an enlarged head 57 and a necked-down tapped portion On the under side of operator 54 are two recesses 5), each of which is adapted to receive a portion of handle $3. With the circuit breaker in the left row of the panelboard of Fig. l, the handle is mounted by inserting the tapped portion 58 of pivot member 56 in tapped hole 61 of cover 16. Circuit opening and closing is obtained by downward and upward movement, respectively, of rotary operator 54 about pivot member 5-6. If it is desired to position the breaker in the right row of the panelboard and still maintain the relative movement of rotary operator 54, i. e., downward for Circuit opening and upward for circuit closing, pivot member 6 and rotary operator 54 are removed and remounted by inserting pivot member 56 through hole 55 of rotary operator 54 into tapped hole 62 in cover 16. The alternate recess thus engages handle 59 and the identical movement for circuit opening and closing is obtained. The handle portions of rotary operator 54 are thus maintained in horizontal alignment above the centerline of cover 16. The circuit breakers can also be positioned vertically in the panelboard rather than horizontally, as in Fig. 1.

In the closed circuit position (Fig. 4), the tip 41 of cradle 22 is retained by latch 42. Tension springs 27 are stressed and maintain the knee of the toggle links 2% 3% to the left of the centerline through pivot pin 34 of cradle 22 and pivot 33 of switch arm 31. Upon circuit opening movement of rotary operator 54, handle 53 is carried longitudinally to the right, rotating operating member 24- about pivot 26 of frame 21. Trip member 49 pivoted at 42; is moved upward and to the right with the assistance of trip member spring 5t]. Further movement of operating member 24 causes the end of trip member 49 to strike projection 45a of common trip bar 45, causing it to rotate about pivot 46. The tip 44 of latch 42 is released and moves downwardly as latch 42 rotates clockwise about pivot 43. Tip 41 of cradle 22 is released and moves upwardly as cradle 22 rotates counterclockwise about pivot 23. Under the bias of springs 27, pivot 28 of links 29, 30 crosses the centerline of pivots 33, 3st bringing springs 27, link 29, and the lower portion of operating member 24 in alignment, as shown in Fig. 5. Contacts as and 37 are rapidly separated. Springs 27 are then in their most relaxed position and are not further stressed because of the coincidence of the centerline of pivots 26 and 33 and the centerline of the outer connection of springs 27 and pivot 26 of operating member 24. Because of this lack V of additional stress the handle 53, the lower portion of operating member 24, and aligned toggle link 29 continue to the right by inertia of the mechanism under the initial force of springs 27 and leaf springs 35. The mechanism is then in the intermediate automatic reset position of Fig. 5. Further movement to the right causes links 29 and 30 through pivot pin 34 to pull downwardly on cradle 22 biasing it clockwise about pivot 23 and towards engagement of tip 41 with latch 42. As the upper portion of operating member 24 moves to the right, shoulder 24a strikes projection 22a of cradle 22 and assists links 29 and 30 in moving tip 41 downwardly into engagement with latch 42. This movement is also assisted by trip member spring 50. As the movement continues, tip 41 strikes the left end of latch 42 and causes it to rotate about pivot 42a and move to the right, as permitted by lost motion slot 4312, until tip 41 clears and is positioned below the end of latch 4-2 and the outer end 44 of latch 12. is engaged with trip bar 4-5. The handle'53 of operating member 24 is thus in the extreme right open circuit position, as shown in Fig. 6, with rotary actuator 54 rotated downwardly to the OFF position, shown in Fig. l. The'knec of toggle links 29, 30 is broken as' shown with all) 4 pivot- 28 to the right of the centerline of pivots 33, 34. The breaker mechanism is thus reset in the open circuit position preparatory to manual movement to the closed circuit position.

Circuit closing is accomplished in a reverse manner with quick make or rapid closing of the contacts being achieved as the pivot 28 moves over center.

The circuit breaker mechanism of the present invention is the trip free type, which will open even if the rotary actuator 54 is held in the closed circuit or ON position. Furthermore, the breaker is quick break in that rapid separation of the contacts occurs upon circuit opening movement.

From the foregoing description it can be seen that a novel circuit breaker is disclosed having automatic resetting as well as quick make and quick break.

Having thus described the invention, reference is had to the appended claims for the scope thereof.

We claim:

1. In a circuit breaker a control mechanism including a frame having a fixed pivot, an operating member pivotally mounted on said fixed pivot, a resilient contactor, a latchable cradle member, an overcenter toggle linkage pivotally interconnected between said cradle member and said contactor, resilient means interconnected between the knee of said toggle linkage and said operating member for overcenter biasing action thereon, said latchable cradle member holding said mechanism in the closed circuit position when latched and being releaseable to permit said control mechanism to move to the open circuit position, the lower pivot point of said toggle linkage and said contactor member being arranged to coincide with said pivot point interconnecting said operating member and said frame after initial operation of said mechanism from the closed to the open circuit position to thereby prevent further stress on said resilient means to permit said latcha'ble cradle member to be relatched by the inertia of said mechanism and the bias of said resilient contactors whereby said mechanism is automatically reset preparatory to circuit closing operation.

2. in a circuit breaker including a control mechanism, a contact or controlled thereby for circuit opening and circuit closing movement, said control mechanism comprising an operating member, a latchable cradle member, an overcenter toggle linkage interconnected between said 'contactor and said cradle member including an upper link and a lower link, resilient means interconnecting said operating member and said linkage for overcenter action thereon, said cradle member upon release permitting said control mechanism to move to the open circuit position, the lower portion of said operating member, said lower link and said resilient means arranged to have coinciding centerlines after initial release of said cradle member to thereby inhibit further stress of said resilient means to permit said mechanism to move to the open circuit position and automatically rela'tch said cradle member preparatory to circuit closing operation.

3. In a panelboard having a plurality of multipole circuit breakers, each including a housing, a cover overlying and secured to said housing, a control mechanism secured in said housing comprising an operating member, a cradle member, a plurality of contactors, an overcenter linkage mechanism interconnecting said cradle member and said contactors, an actuating mechanism including a stud member secured to said operating member, a handle secured to said stud member and extending through a slot in said cover, an insulating barrier below said cover and pivotally interconnected between a projection extending below said cover and said handle to be actuated thereby to close said cover slot at all times, a rotary operator overlying said cover and removably secured thereto, said rotary operator having a plurality of recesses adapted to receive and engage said handle. said rotary operator and said cover having cooperating formation for mounting said rotary operator to provide identical handle movement to actuate said circuit breaker to open and closed circuit positions regardless of the positioning of said circuit breaker in said panelboard.

4. In a panelboard having a plurality of multipole circuit breakers, each including a housing, an insulating shield overlying said housing, a cover overlying said insulating shield and secured to said housing, said shield and said cover having a handle opening therethrough, a control mechanism secured in said housing comprising an operating member, a cradle member, a plurality of contactors, an overcenter linkage mechanism inte connecting said cradle member and said contactors, an actuating mechanism including a stud member secured to said operating member, a handle secured to said stud member and extending through a slot in said shield and said cover, an insulating barrier interposed between said shield and said cover and pivotally interconnected between a projection extending from said cover and said handle to be actuated thereby to close said cover slot at all times, a rotary operator overlying said cover and removably secured thereto, said rotary operator having a plurality of recesses adapted to receive and engage said handle, said rotary handle and said cover having cooperating formation for mounting said rotary operators to provide identical handle movement to actuate said circuit breaker to open and closed circuit positions regardless of the positioning of said circuit breaker in said panelboard.

5. In a multipole circuit breaker a handle mechanism including an insulating shield, a cover, each having a handle opening therein, a barrier interposed between said shield and said cover and pivotally secured to said cover for maintaining a closure of said handle opening, a rotary operator overlying said cover, means for securing said operator to said cover, said operator having a plurality of recesses therein, said cover and said operator having cooperating formations to permit said operator to be selectively positioned on said cover.

6. in a multipole circuit breaker having a control mechanism including an operating member, a handle mechanism comprising a stud member secured to said operating member, a removable handle threadably secured to said stud member, an insulating shield, a cover, each having a handle opening therein, a barrier interposed between said shield and said cover and pivotally secured to said cover for maintaining a closure of said handle opening, a rotary operator overlying said cover, means for securing said operator to said cover, said operator having a plurality of recesses therein, said cover and said operator having cooperating formations to permit said operator to be selectively positioned on said cover.

7. In a panelboard having a plurality of multipole circuit breakers, each including a housing, an insulating shield overlying said housing, a cover overlying said insulating shield and secured to said housing, said shield and said cover having a handle opening therethrough, a control mechanism secured in said housing comprising an operating member, a cradle member, a plurality of contactors, ,an overcenter linkage mechanism interconnecting said cradle member and said contactors, an actuating mechanism including a stud member secured to said operating member, a handle secured to said stud member and extending through a slot in said shield and said cover, an insulating barrier interposed between said shield and said cover and pivotally interconnected between 2. projection extending from said cover and said handle to be actuated thereby to close said cover shot at all times.

8. In a circuit breaker the combination of a control mechanism and a handle mechanism operatively connected to said control mechanism; said handle mechanism comprising an insulating shield, a cover, each having a handle opening therein, a barrier interposed between said shield and said cover and pivotally secured to said cover for maintaining a closure of said handle opening, a rotary operator overlying said cover, means for securing said operator to said cover, said operator having a plurality of recesses therein, said cover and said operator having cooperating formations to permit said operator to be selectively positioned on said cover; a frame having a fixed pivot, an operating member pivotally mounted on said fixed pivot, a resilient contactor, a latchable cradle member, an overcenter toggle linkage pivotally interconnected between said cradle member and said contactor, resilient means interconnected between the knee of said toggle linkage and said operating member for overcenter biasing action thereon, said latchable cradle member holding said mechanism in the closed circuit position when latched and being releasable to permit said control mechanism to move to the open circuit position, the lower pivot point of said toggle linkage and said contactor member being arranged to coincide with said pivot point interconnecting said operating member and said frame after initial operation of said mechanism from the closed to the open circuit position to thereby prevent further stress on said resilient means to permit said latchable cradle member to be relatched by the inertia of said mechanism and the bias of said resilient contactor whereby said mechanism is automatically reset preparatory to circuit closing operation; a handle, a threaded stud connecting said handle to said operating member, said handle passing through said handle opening to engage one of said recesses in said rotary operator so that said rotary operator may be used to operate said control mechanism.

9. In a circuit breaker, a control mechanism comprising a frame having a first, a second and a third pivot, an operating member pivotally mounted on said first pivot, a resilient contactor pivotally mounted on said third pivot, a cradle member pivotally mounted on said second pivot, a latch operatively engageable with said cradle to hold said control mechanism in the closed circuit position when latched and when unlatched to permit said control mechanism to move to the open circuit position, a toggle linkage having a knee, one end of said toggle linkage pivotally connected to a lower pivot on said contactor and the other end pivotally connected to an upper pivot on said cradle, a resilient means connected between said knee and a point on said operating member; said operating member, said contactor, and said cradle member being operatively connected so that when said resilient means is fully relaxed said lower and first pivots will coincide and said point, said knee, and said first pivot may be joined by a straight line; said latch when unlatched after said control mechanism is operated to said closed position, releasing energy stored in said resilient contactor and said resilient means to thereby reposition said control mechanism so that said resilient means is fully relaxed and the momentum of said mechanism may automatically bring the mechanism to said open circuit position where said cradle will be engaged by said latch.

References Cited in the file of this patent UNITED STATES PATENTS 1,930,980 Maibohm Oct. 17, 1933 2,043,470 Dyer et a1. June 9, 1936 2,210,261 Sachs Aug. 6, 1940 2,294,838 Dorfman Sept. 1, 1942 2,332,496 Baxter Oct. 26, 1943 2,371,672 Bolesky Mar. 20, 1945 2,414,554 Pierce Ian. 21, 1947 2,466,820 Oberschmidt Apr. 12, 1949 2,467,797 Wise Apr. 19, 1949 2,534,938 Woodard Dec. 19, 1950 2,600,223 Dorfrnan et al. June 10, 1952 2,610,272 Platz Sept. 9, 1952 2,646,488 Platz July 21, 1953 

